The invention relates to the art of forming glass articles from molten glass, and more particularly to the initial preforming of a patty of molten glass into a disc shaped parison which may be subsequently formed into a finished article by vacuum forming, blowing, pressing, blanking and other known forming techniques.
In the past, with the exception of vacuum forming wherein rolled or sheet glass is normally utilized, the remaining operations generally begin with the depositing of a gob of molten glass within a mold which may then be pressed and/or blown or blanked into a finished article. The viscosity of a gob for a medium size pressing may be in the vicinity of about 10,000 poises, and accordingly relatively high pressing forces are required in order to press-form the gob between a mold and plunger into a formed article. Thus, relatively low viscosity glasses, which may be delivered with a viscosity of below 1000 poises, are not easily adaptable for use with such aforementioned conventional glass forming processes.
U.S. Pat. No. 3,436,202 discloses a pressing apparatus which is adapted to accommodate low viscosity glasses which may be fed by forced stream feeding such as shown in U.S. Pat. No. 3,351,449. The feeding patent discloses the formation of a circular patty within a mold whereas the forming patent sets forth an apparatus for pressing such circular patty prior to the same being indexed horizontally in order to avoid distortion of the patty which would be occasioned upon the implementation of horizontal or transverse motion to the low viscosity molten patty.
The present invention, however, discloses method and apparatus for acting upon and distributing the patty deposited by such feeder patent so as to provide a preformed disc-shaped parison of low viscosity glass which may then be easily formed into various articles utilizing such known techniques as pressing, blowing and vacuum forming.
It thus has been an object of the present invention to improve upon the known technology of delivering low viscosity glasses so as to be able to utilize such glasses in a variety of forming techniques.